Computer networks often use intermediate devices to interconnect disparate networks together. For example, Field Area Routers (FARs) are routers in the Smart Grid network that are installed in the field at locations such as electricity poles. In one direction (often called the “southbound”), FARs connect LLN (Low power and lossy Networks) domains that may comprise a large number of devices such as sensors and actuators (e.g., smart objects or Minimalistic Connected Objects), often using low power wireless and/or power-line communication (PLC) links. FARs usually act as directed acyclic graph (DAG) roots, through which all of the traffic from the LLNs to a control center is transiting, and thus play a critical role in the infrastructure. In the reverse direction (often called the “northbound”), these routers illustratively communicate with the Utility Control Center in another network using various wireless backhaul technologies such as 2G, 3G, LTE, Wimax, etc., as will be readily understood in the art.
Often, these particular types of backhaul links that interconnect networks may be unreliable, and could lose their connection (e.g., wireless coverage) for several hours at a time. FARs, for instance, rarely have a connection to high-speed reliable uplinks, thus they use of unreliable or lossy links to connect to the control center. These FARs, in particular, may be connected to various devices such as electric/gas/water meters, relays, actuators, etc., where these devices send status message and/or receive control messages from applications in the Utility Control Center. Typically, these devices have limited CPU processing power and memory, and they cannot implement highly complex algorithms. However, it is desired for these types of devices, as well as for many other types of devices and network environments, to transmit the data reliably from the devices across the unreliable backhaul links, regardless of the delay associated with the delivery.